What is the difference between the two versions of 'to be'?

There are two different verbs meaning 'to be' in Spanish- ser and estar. They are used for different things. 

The uses for ser can be remembered using the acronym 'Doctor':

Date, Occupation, Characteristic, Time, Occupation, Relation. 

The uses for Estar can be remembered using the acronym 'Place'. 

Position, Location, Action, Condition, Emotion.